spencer michels of the pbs "newshour" reports. >> i wanted the world to know what a wonderful, incredible person she was. >> reporter: for more than a decade, nick and amanda wilcox have been advocating timely treatment and early intervention for the severely mentally ill. in the hopes they won't become violent. 12 years ago, their 19-year-old daughter, laura wilcox, a college sophomore, was murdered while she was working over christmas break in a mental health clinic in nevada county, california. >> at about 11:30, a client at the clinic came in and shot laura four times at pointblank range through the glass. >> what we know now after the fact is that he had late onset paranoid schizophrenia. >> reporter: laura's murderer, scott thorpe, killed two others then went home and took a nap. he was eventually sentenced to a locked mental hospital for life. >> we felt that laura's death was a result of a failed mental health system. >> we wanted to help prevent people from being so mentally ill that they would commit a violent act. >> reporter: helen thompson, a former psychiatric nurse, was a c